When GE corn was introduced in the mid-90s, Mexico was inhospitable to the new-fangled crop. The country's National Biosecurity Commission established a (non-legally binding) moratorium on genetically engineered corn in 1998 as a means to safeguard what is considered to be the planet's cradle of maize cultivation.

Corn has been carefully tended in Mexico for eight millennia and environmental conservationists report that thousands of peasant varieties are still grown throughout the country. With an estimated 75 per cent of the planet's biodiversity vanished as of 1995, Mexico's heterogeneous corn fields are a rare vestige of the age prior to the "Green Revolution" era that is responsible for the artificially and unhealthily homogenous industrial agriculture that is prevalent now.

Introducing GE corn to Mexico would sound the death knell for this precious ecology as it is widely agreed that GE crops cannot co-exist with conventionally bred seeds.

Thousands of tonnes of corn that began inundating Mexico from, primarily, the US (mostly for non-human consumption) after the signing of NAFTA in 1994 ensured that the promiscuous plant's pollen blew onto the pristine fields of small farms. As of today, it is estimated that at least one per cent of Mexico's corn has traces of GE.

But perhaps of more immediate threat to the magnificent biodiversity of Mexico's maize is the country's politicians' willingness to succumb to the pressure of big biotech companies. Over his past six years in office, Calderon has overseen the whittling away of the above-mentioned safeguards.

In 2007, Mexico's Chambers and Congress passed the "Law of Seeds" that prohibits farmers from trading or selling seeds they had cultivated. And two months after Calderon met with the president of Monsanto, Hugh Grant, at the annual World Economic Forum in Davos, Switzerland, in January 2009, he lifted the 1998 moratorium on GE corn. This triggered a flood of applications for permits - the first of which came from Monsanto - to begin planting genetically modified maize.

And, earlier this year, Mexican legislators came close to passing a bill that would modify the Federal Law on Plant Varieties which would promote privatising patents of certain breeds of plants.

Comparable to how the enclosure acts in England created a landless working class, this legislation in Mexico would create a class of seedless farmers, planting the "property" (seeds) of transnational corporations that have monopolised the market for maize seeds. Thus, what is now controlled by the country's farmers would become the private property of corporations.

However, Mexican farmers, small and large, responded to the proposed bill with forceful opposition, knowing full well the devastation that mono-cropping with bioengineered seeds would have on them - the examples provided by South and East Asia doubtless providing a stark warning.

Veronica Villa, from the Colonia Insurgentes Mixcoac in Mexico City, explained to me that both commercial farmers of maize in the North and small indigenous farmers in the South (whose agricultural fields remain largely collective property and are used primarily to feed themselves) both fear the onslaught of GE corn.

Those in the North fear the high costs and debts associated with transgenic corn, while the farmers in the South are the primary protectors of thousands of ancient varieties.

Ecological destruction

On the eve of elections, in a small but important victory, the highly unpopular bill was not presented to Congress, and the grassroots agricultural movement succeeded in keeping their own demise at bay for that moment. However, the bill is still pending and will likely be floated before Congress at a more politically opportune time.

"While biotech companies have tried to float their products as being necessary in an era of climate-change, empirical studies have shown that the best defence for corn-farmers is diversity."

Also still pending approval are requests by Monsanto and DuPont to plant 2,500,000 hectares of GM corn, which would signal a watershed in the agricultural landscape of Mexico. While Calderon left office before granting his blessing on the arrangement, all signs indicate that new President of Mexico, Enrique Pena Nieto, will be happy to put his imprimatur on the sweetheart deal for Big Biotech.

Mexico's deputy agriculture secretary, Mariano Ruiz, told the press that the new president supported the introduction of large-scale GMO corn cultivation, saying, "I think we are in agreement generally over the importance of having this instrument, and that farmers have the tool of genetically modified organisms".

Of course, farmers have all the tools they need without the meddling of chemical companies. While biotech companies have tried to float their products as being necessary in an era of climate-change, empirical studies have shown that the best defence for corn-farmers is diversity.

Doug Gurian-Sherman, Senior Scientist with the Union for Concerned Scientists, warns of the far-reaching impact that supplanting Mexico's diverse maize plants with an industrial model could have. "Their diverse seeds contains many important traits like drought tolerance and pest resistance that we need going forward. If we lose them, we're going reduce our ability to respond to climate change and other threats to maize."

Meanwhile, as Monsanto burrows into Mexico's cornfields, the biotech giant digs its rapacious claws further into the US - its single largest source of profits. The US Congress is expected to pass the FY 2013 Agriculture Appropriations Bill with the disturbingly anti-democratic "Monsanto-rider" embedded in the 90-page agreement, which would require the Secretary of Agriculture to override any federal court injunction on a GE crop and grant it a temporary permit.

As long as politicians do not stand up for the health of their citizens or their land, biotech companies will reap profits in the grim wake of human and ecological destruction.

Charlotte Silver is a journalist based in San Francisco and the West Bank. She is a graduate of Stanford University.